Nutritional composition of pasture plants and their digestion and utilization by horses

Nutritional value of forages starts with the structures, properties and roles of the nutrient molecules. Sunlight is the stimulus for green plants to convert carbon dioxide and water into a simple sugar. The sugar is then used as an energy source for other processes in the plant and as a building block for structural (fibrous) carbohydrates and non-structural (energy storage) carbohydrates and lipids. Slight variations in sugar structures determine how they are arranged in polysaccharides, mainly starch, cellulose and hemicellulose. Most of the structural carbohydrates, cellulose and hemicellulose, are deposited in plant cell walls in increasing amounts as plants mature. Determination of the concentrations of nutrients in feedstuffs is a developing science. Information on nutrient concentration of forages is used along with nutrient requirements to formulate optimal diets for horses with varying needs.